Beydoun M A, Beydoun H A, Dore G A, Canas J-A, Fanelli-Kuczmarski M T, Evans M K, Zonderman A B
Laboratory of Epidemiology and Population Sciences, NIH Biomedical Research Center, National Institute on Aging, IRP, Baltimore, MD, USA.
Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
Transl Psychiatry. 2016 Sep 20;6(9):e895. doi: 10.1038/tp.2016.180.
Total white blood cell count (TWBCC) and percentage (%) composition of lymphocytes (PL) or neutrophils (PN) are linked to mid- and late-life depression, though sex-specific temporal relationships between those inflammatory markers and depressive symptoms remain unclear. The association between inflammation and depressive symptoms in longitudinal data on ethnically and socioeconomically diverse urban adults was examined with two hypotheses. In hypothesis 1, we examined the relationship between TWBCC, PL and PN with change in level of depressive symptoms from baseline to follow-up, stratifying by sex. In hypothesis 2, we examined reverse causality, by testing the relationship of depressive symptoms with change in TWBCC, PL and PN. Multiple linear mixed-effects regression models were performed to examine both the hypotheses. The sample sizes of participants (n) and repeated observations (n') were: Hypothesis 1 (n=2009; n'=3501); Hypothesis 2 (n=2081; n'=3560). Among key findings (Hypothesis 1), in women, higher TWBCC was linked to a faster increase in depressive symptom total score (γ1112±s.e.: +0.81±0.28, P=0.003), with a slower increase over time in the positive affect subdomain coupled with faster increases in depressed affect and somatic complaints. Among women, baseline score on somatic complaints was positively associated with low PN (γ01a=+1.61±0.48, P<0.001) and high PL (γ01a=+1.16±0.45, P=0.011), whereas baseline score on positive affect was inversely related to higher PL (γ01a=-0.69±0.28, P=0.017). Results among men indicated that there was a positive cross-sectional relationship between low TWBCC and depressive symptoms, depressed affect and an inverse cross-sectional relationship with positive affect. However, over time, a low TWBCC in men was linked to a higher score on positive affect. There was no evidence of a bi-directional relationship between WBC parameters and depressive symptoms (Hypothesis 2). In sum, TWBCC and related markers were linked to depressive symptoms, mostly among women. Further longitudinal studies are needed to replicate this sex-specific association.
白细胞总数（TWBCC）以及淋巴细胞百分比（PL）或中性粒细胞百分比（PN）与中年及晚年抑郁症有关，不过这些炎症标志物与抑郁症状之间的性别特异性时间关系仍不明确。我们通过两个假设检验了种族和社会经济背景各异的城市成年人纵向数据中炎症与抑郁症状之间的关联。在假设1中，我们按性别分层，研究了TWBCC、PL和PN与从基线到随访期间抑郁症状水平变化之间的关系。在假设2中，我们通过检验抑郁症状与TWBCC、PL和PN变化之间的关系来研究反向因果关系。我们使用多元线性混合效应回归模型对这两个假设进行了检验。参与者的样本量（n）和重复观测次数（n'）分别为：假设1（n = 2009；n' = 3501）；假设2（n = 2081；n' = 3560）。在主要研究结果（假设1）中，在女性中，较高的TWBCC与抑郁症状总分的更快增加相关（γ1112±标准误：+0.81±0.28，P = 0.003），积极情感子领域随时间的增加较慢，同时抑郁情感和躯体不适增加较快。在女性中，躯体不适的基线得分与低PN（γ01a = +1.61±0.48，P < 0.001）和高PL（γ01a = +1.16±0.45，P = 0.011）呈正相关，而积极情感的基线得分与较高的PL呈负相关（γ01a = -0.69±0.28，P = 0.017）。男性的研究结果表明，低TWBCC与抑郁症状、抑郁情感之间存在正的横断面关系，与积极情感存在负的横断面关系。然而，随着时间的推移，男性的低TWBCC与积极情感得分较高相关。没有证据表明白细胞参数与抑郁症状之间存在双向关系（假设2）。总之，TWBCC及相关标志物与抑郁症状有关，主要是在女性中。需要进一步的纵向研究来验证这种性别特异性关联。
